package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.SetOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;

    @Override
    public Result follow (Long followUserId, Boolean isFollow) {
        Long userId = UserHolder.getUser ().getId ();
        String key = "follows:" + userId;
        if (isFollow) {
            //关注
            Follow follow = new Follow ();
            follow.setUserId (userId);
            follow.setFollowUserId (followUserId);
            boolean isSuccess = save (follow);
            if (isSuccess) {
                stringRedisTemplate.opsForSet ().add (key, followUserId.toString ());
            }
        } else {
            //取关
            boolean isSuccess = remove (new QueryWrapper<Follow> ()
                    .eq ("user_id", userId).eq ("follow_user_id", followUserId));
            if (isSuccess) {
                stringRedisTemplate.opsForSet ().remove (key, followUserId.toString ());
            }
        }
        return Result.ok ();
    }

    @Override
    public Result isFollow (Long followUserId) {
        Long userId = UserHolder.getUser ().getId ();
        Integer count = query ().eq ("user_id", userId).eq ("follow_user_id", followUserId).count ();
        return Result.ok (count > 0);
    }

    @Override
    public Result followCommons (Long id) {
        //当前用户
        Long userId = UserHolder.getUser ().getId ();
        String key1 = "follows:" + userId;
        String key2 = "follows:" + id;
        Set<String> intersect = stringRedisTemplate.opsForSet ().intersect (key1, key2);
        if (intersect == null || intersect.isEmpty ()) {
            return Result.ok (Collections.emptyList ());
        }
        List<Long> userIds = intersect.stream ().map (Long::valueOf).collect (Collectors.toList ());
        List<UserDTO> userDTOList = userService.listByIds (userIds)
                .stream ()
                .map (user -> BeanUtil.copyProperties (user, UserDTO.class))
                .collect (Collectors.toList ());
        return Result.ok (userDTOList);
    }
}
